1. Field of the Invention
The present invention relates to electrodes for electrolysis of water.
2. Description of the Prior Art
Electrodes for the electrolysis of water are well known in the art. Such electrodes as well as processes for their production evolved from the technology developed for fuel cells. Such cells are described, for example by Carl Berger, Handbook of Fuel Cell Technology, pages 401-406, Prentice Hall 1968 and H. A. Liebafsky and E. J. Cairns, Fuel Cells and Fuel Batteries, pages 289-294, John E. Wiley and Sons, 1968. The demand for exactly defined reaction zones requires a multi-layer structure and special treatment processes of such fuel cell electrodes.
The above described electrodes, however, are too complicated and their production methods too complex and expensive for use in the electrolysis of water. This applies in particular to production methods utilized in large industrial plants for the production of hydrogen on an efficient and economical basis.
Electrodes specifically constructed for the electrolysis of water are likewise known in the art. For example, LaConti et al U.S. Pat. No. 4,039,409 describes an electrode for electrochemical systems such as electrolysis and oxygen concentrator cells which contain an active reduced platinoid electrocatalyst comprising platinum oxide and from 5 to 60% ruthenium oxide. The catalytic electrode and cathode are positioned on opposite sides of a cationic exchange membrane.
Various methods of forming metal electrodes are likewise known in the art. For example, Alfenaar et al, U.S. Pat. No. 4,127,468 describes a method for preparing a metal electrode wherein a basis metal electrode is contacted with a solution of an alloying element compound which is reduced in situ to form the free alloying element which forms an alloy with the basis-metal.
The electrodes described above, as well as those presently utilized commercially, leave much to be desired with regard to their mechanical and chemical properties. This applies generally also with regard to the catalysts presently used.